Ceiling fans powered by electric motors have been used for years in circulating air. They typically have a motor within a housing mounted to a downrod that rotates a set of fan blades about the axis of the downrod. The fan may also include a light fixture.
Ceiling fan light fixtures typically include one or more glass light diffusers which may be in the form of a single globe or a plurality of shades. Each diffusor is retained by a mounting structure affixed to the ceiling fan. The glass light diffusers typically include a lower portion which may include an ornament design and may assume a variety of shapes and configurations, and a substantially cylindrical portion extending upwardly from the lower portion. The light diffusers of conventional ceiling fan light fixtures are typically retained in one of the following two ways. A plurality of circumferentially spaced set screws may be used, with the set screws protruding radially inwardly through a cylindrical flange of the mount structure affixed to the fan, until they are in contacting engagement with the neck portion of the glass light diffusor. The light diffusor is then retained in place by the friction created by the contacting engagement between the set screws and the neck portion of the light diffusor. The force exerted by the set screws may crack the fragile neck of these glass diffusers should they be overly tightened.
In other conventional ceiling fan light fixtures, the substantially cylindrical neck portion of the light diffusor includes a helical threaded portion which engages protuberances in an annular flange of the mount structure, as shown in U.S. Pat. No. 6,428,188. The manufacturing of these light diffusers may be difficult due to the multiple protuberances of the neck of those globes or shades which are threaded in place. It has been found that the glass material does not hold tolerances well as the material can shrink or expand in diameter due to variables in the molding process.
In view of the foregoing deficiencies associated with known light fixtures in general, and light fixtures for ceiling fans in particular, there remains a need for a light diffusor that is easy to manufacture and which will not break should mounting screws be utilized. It thus is to the provision of such that the present invention is primarily directed.